Friday, March 23, 2012

No More Cars?

I read a cool article in the New York Times this morning where they wrote that large numbers of young people are no longer interested in cars.What an amazing proposition. I wonder why it is?

Cars are controversial. This sounds less radical now than when I was growing up in the '60s and '70s, when car ownership was part of the American Dream. There are so many reasons that cars are problematic. I won't go into them here, well, at least not most of them.

But all this reminds me of a presentation my students gave the other day. They were talking about solar energy, which they claimed had about a 20% efficiency rate. This didn't sound half bad to me. After all, solar energy is emission-free and relatively low-impact. If you compare it to the efficiency of the internal combustion engine (about 5% of that energy is transferred from your gallon of gas to the wheels of your car) it's an incredibly effective way of capturing light energy.

During the Q & A after the presentation I thought there was a pretty good "teachable moment." Last semester we learned about photosynthesis. With all the discussion of the internal workings of the chloroplast I didn't have a chance to discuss energy efficiency with my students. But here was my chance. Internal combustion motor, approximately 5%. Solar power generators, approximately 20%. Photosynthesis? About 33% efficiency.

How does this translate? About 33% of all the light that hits the leaf goes into the production of sugars that build the plant body (cellulose) or fuel the respiratory process (glucose). Pretty amazing way plants have evolved to utilize sunlight.

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Growth = Movement

Plants don't "move" but plant tissue stretches, warps, bends, contracts and expands in response to growth stimuli. We can see evidence of this kind of slow-motion movement in any plant form we observe. In this detail of old tree we can see how woody tissue responded over decades of growth to the "knot" in the center.

Dune Stabilizers

Grasses like this help stabilize dunes and at the same time move with the wind.

Bittersweet Double Helix

Most plants express some kind of helical growth form. Many plants also exhibit thigmotrophy, which is a kind of movement toward other surfaces. Ivy that grows on a wall, moss growing along the pavement, and climbing vines like this bittersweet are all examples of thigmotrophy. This kind of growth allows various plants to reach sunlight, to retain water, and to make their fruit available for dispersal.

Plant Movement

Plants search out the light and move toward it. Stems elongate toward the light in etiolation, seen in this photo.

Migrating Crops

Corn, which was originally cultivated in Central America, has migrated to every part of the world through the activities of its human partners.

Partners Help Plants Move

Pollinators and other partners help plants get around. This unlikely pollinator will spread pollen from one individual to the next.

Nicotiana

Plant some Nicotiana outside your afternoon-shade window and you'll get great aroma all summer long.

The smell of fresh apples

Mmm...a barrel of fresh apples smells great.

Magnolia

Magnolia's wonderful aroma is remembered all year.

Pineapple Patterns

The appearance and aroma of a pineapple are distinctive but they are only part of its relevant characteristics.

Fiddlehead

The characteristic fern shape, circinnate vernation, can be seem in other plants too.

Milkweed Seeds

It's no accident that these seeds are arranged like the pineapple above. The milkweed and pineapple share a common ancestor that they inherited this body plan from.

Inspiration

Velcro was inspired by the lowly burdock plant.

Darwin's Garden

These formal plantings are part of Darwin's gardens at Downe House. He also used extensive experimental gardens and greenhouses.

Milkweed and Bumblebee

Looking closely at a flower and its pollination partner teaches us about the Naturalistic Philosophy.

Our garden

A view of our garden in Cambridge, Massachusetts.

Pattern and Process

Looking closely at all parts of the plant helps us develop an awareness of its patterns and process

About Me

I communicate science to non-scientists. My interest in the intersection between art and science, which I consider to be closely related practices, is the focus of two essay collections I am working on. As a Harvard PhD I realized that the work we do in the library and laboratory, while worthy in and of itself, does not necessarily translate to normal people. Bridging that gap is my goal in my teaching practice and in these posts. I teach college sophomores at Boston University and I teach in the sustainability program at the Boston Architectural College.